She largely worked for her parents' company : which got no publicity at all.
Well, if you believe that...but certainly it has got a great deal of publicity, as its trotted out every time its asked just what this woman did between graduation and marrying. Although it remains very mysterious as to what she actually did.
So she did have as much financial independence as any child of a business owner needs.
I have never heard of this rule before. I know plenty of people who own businesses, whose children have jobs and careers outwith those businesses. The Middleton party planning business is actually a pretty small one and seems unlikely to provide gainful employment for 3 children, not lest because of its limited remit.
Face up to it, the management by Buckingham Palace of William's potential brides has backfired slightly, because female graduates who do actually have to go out and get jobs, and in fact most working females, find those excuses for not working a bit pathetic. Therefore a lot of women like me will always be a bit sceptical of Kate because she simply didn't do anything with her life in that long period between graduating and marrying.
The Royal Family are a bit of an outlier on the moneyed, privileged set anyway. Not the most popular choice for a gel to marry into, have to follow certain rules which means they can't do a lot of the fun stuff.